1. Field of the Invention
The present invention relates to a product of white-light emitting diode which requires only two rounds of baking, and more particularly to a manufacturing process of the white-light emitting diode. The process offers advantages of facilitating process, increasing output and effectively controlling product quality; and the product itself gives good emitting quality and stable white light emitting effect.
2. Description of the Prior Art
The ever improving process of an LED allows the production from a large size face panel, LED applications, such as Xmas tree lighting, flashlight and traffic sign, grow fast by year and the market place of the diode industry also enjoys rapid expansion. As illustrated in FIG. 1, in the structure of a white-light emitting diode manufactured by the process of the prior art of the present invention, a light-emitting chip (2) is attached to a bowl (13) of a diode (1) with a conductive silver glue (3), then baked for two hours in an oven at the temperature of 150.degree. C. and secured in position. Gold wire (5) is used to respectively butted to diode pins (11, 12) then the entire chip (2) is masked with fluorescent glue (4) baked for two hours at 140.degree. C. The entire process takes four working hours. Longer hours means being vulnerable to produce the defective ones. In addition, the process requires that the mask area of conductive silver glue (3) not to be greater than one third of the light emitting chip (2) since the greater mask area will affect the white-light emitting quality of the entire white-light emitting diode; as a result, the number of inferior quality products beyond the tolerance.
Another prior art of the present invention requires three rounds of baking process. As illustrated in FIG. 2, the light emitting chip (2) is attached in the bowl (13) of the diode (1) with the conductive silver glue (3) and baked for two hours in the oven at 150.degree. C. When secured, the gold wire (5) is used to respectively butt the pins (11 and 12) from two electrodes and the entire light-emitting chip (2) is masked with transparent glue (6) to be baked again for two hours in the oven at 150.degree. C. When secured, and the upper layer of the entire light-emitting chip (2) is coated with fluorescent glue (4) to be bonded in the oven at 150.degree. C. for one hour. The entire process takes three rounds of baking and five working hours to complete. The same defectives as discussed in the first prior art are found in this process, too.
So far it is impossible to produce a white-light emitting diode by causing a light-emitting chip to directly create white-light. Each color light gives own spectrum characteristics at particular wavelength. The present invention achieves white-light emitting effect by having the color light from the LED chip to emit through fluorescent glue at given wave length to incorporate both wave lengths of the color light and that from the LED chip into the range of that of white light.